A THD-reduction high-efficiency audio amplifier using inverter-based OTAs with filter-output feedback

作者：Hwang Yuh Shyan^*; Shen Jian Hong; Chen Jiann Jong; Fan Ming Ren

来源：Microelectronics Journal, 2014, 45(1): 102-109.

DOI：10.1016/j.mejo.2013.10.007

• Class-D amplifier
• Pulse-width modulation
• Low voltage
• Inverter

This paper presents an integrated low-voltage THD-reduction high-efficiency class-D audio amplifier using inverter-based operational transconductance amplifiers (OTAs). We propose a negative feedback loop which can compensate for external perturbations and improving output precision. The compensator increases the audio-frequency loop gain, and leads to a better rejection of audio-frequency disturbances. The use of inverter-based OTA and comparator provides low-voltage operation and low-power dissipation. The audio amplifier operates with a 1.5 V supply voltage with maximum power efficiency of 90%. The proposed class-D amplifier was implemented using a TSMC 0.18-mu m 1P6M CMOS process, and the active chip area is 1.87 mm(2).

• 出版日期2014-1